Bolt Size on CPS

Just did mine on a 92XJ cherokee, I'm pretty sure it was 7/16. Be really careful, on mine there's a plastic flap the sensor goes through that kept flipping up. I loosened the bolts a couple of threads worth and did the rest by hand. From the reading after I asked questions about my sensor, if you drop the bolts in, you have to pull the tranny to get them back!

Thanks Jeff, Just the answer I was looking for. Everything else has been coming up metric on this thing though. Hmm. At least I only have one bolt to worry about. Thanks again. Denny

I thought it was metric, now that you mention it. If you take a 7/16s, you might want to take a 12mm also. These are nearly equivelent sizes, and sometimes they can get mixed up, especially when you are working by braille.

For some reason, 11mm sticks in my mind but at least that cuts down on the number he has to carry. I always slap a piece of duct tape over that stupid cover just because I'm a great believer in Murphy. Sure as heck, if you drop one it goes in the wrong hole.

BTW, if it will start at all it is a whole lot more pleasant to work > I thought it was metric, now that you mention it. If you take a 7/16s, you

Thanks CRWLR, turned out to be 7/16. Just spent the worst ever time under a Jeep ever I had. A COLD Jeep at that. Took 3 extensions and working on my back, over my head and by braille. For all following this, the CPS didn't fix the no start problem. I'm watching the tow truck pulling away as we speak. Thank you everybody for the great help and assistance on this. I learned a lot, but not quite enough. I'll post the final outcome, if there is one. Denny

Thanks Bill. I certainly will, if only to prevent someone else's pain. WHy doesn't this stuff happen in the summer? I know, I know, why don't I have a nice heated garage, lift, that 2,000 piece Craftsman tool set, etc, etc.

Check the ground strap from the rear of the engine head to the firewall!

I has a dead CPS thing and replaced it, got 20 feet.

My mesh cable was rotten.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

D wrote:

D did pass the time by typing:

Just got back from work and read your email.

bummer :(

On the bright side, a new sensor will probably help the ZJs performance and you now have a spare. Can't have too many spare parts. :)

Hope your Jeep gets feeling better.

Mike Romain did pass the time by typing:

Seems sometime in the 92/93 run Jeep started using a ground cable attached off the lower coil mounting bolt.

$5 says it's the PCM. Why D/C decided to put the ignition module inside the PCM, I don't know, but after changing the CPS and the cam sensor in the distributor, I ended up putting a PCM in my wife's '93.

-- Old Crow '82 Shovelhead FLT 92" 'Pearl' '95 Jeep YJ Rio Grande ASE Certified Master Auto Tech + L1 TOMKAT, BS#133, SENS, MAMBM, DOF#51

Bill sez:

If I remember, they wanted like $700 at the dealer. I found one at the junkyard for $150. I was skeptical(sp?), because the test flow chart in the FSM that I borrowed was so simple. I could think of a lot of things in the circuit you could test(and a GM SM would have had you check) besides what the flow chart tested before wanting to replace the PCM. I did all the other checks I wanted before buying the PCM, satisfying my curiosity, I suppose. Then I went and got the PCM, bolted it in, hooked it up and started the Jeep. My wife said hardly anything about the $100 worth of sensors I bought that didn't fix the problem ;-)

-- Old Crow '82 Shovelhead FLT 92" 'Pearl' '95 Jeep YJ Rio Grande ASE Certified Master Auto Tech + L1 TOMKAT, BS#133, SENS, MAMBM, DOF#51

Just an FYI for those interested.

I had what I thought was a CPS problem in my 88XJ. Would run just fine and then quit going down the road and not restart. It would do this randomly.

I replaced the coil and ignition module, no joy.

I cleaned all the grounds in the engine bay, no joy.

I replaced the CPS, no joy.

By this time my wife was getting pretty pissed since she mainly drives this jeep, cause she loves it.

After reading the TSB about replacing the CPS circuit with one that bypasses the big connector on the firewall in front of the driver I disconnected the connector (which is full of some kind of grease) and cleaned all the connetions, male and female. The Jeep has run fine since.

The TSB says that the CPS circuit encounters high resistance in the connector which of course causes the signal to the ECM to fail.

Maybe this summer I'll reroute the CPS circuit but it's 12 degrees outside now so I think I'll wait.